feat(kvb-coach): run the short coach at the first prompt of every full hour

hooks/reminder.sh claims the current clock hour with an atomic mkdir under ~/.claude/.coach-hours/, so only the first prompt of the hour across all agents gets the COACH HOUR hint (at most three lines, most urgent area first, then the request); earlier hours are removed. enable-plugins.js registers it next to the kvb-dream reminder. test_coach covers once per hour, silence within the hour and the cleanup; test_dream checks the single registration. Operator order 2026-11-03.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

tests/test_dream.py

@@ -148,6 +148,7 @@ class TestSettingsRegistration(unittest.TestCase):
         data = self._patch()
         entries = json.dumps(data["hooks"]["UserPromptSubmit"])
         self.assertEqual(entries.count("kvb-dream/hooks/reminder.sh"), 1)
+        self.assertEqual(entries.count("kvb-coach/hooks/reminder.sh"), 1)
         self.assertNotIn("tune/hooks/reminder.sh", entries)
         gate = json.dumps(data["hooks"]["PreToolUse"])
         self.assertEqual(gate.count("kvb-org-organize/scripts/council.py"), 1)